FIELD OF THE INVENTION
The present invention relates to a novel waterproof material for civil engineering works and buildings, and a method for applying a waterproof layer. More specifically, it relates to a method for forming a waterproof layer in a short period of time by a simple spread operation and light irradiation, and a waterproof material which can control environmental pollutions such as the emission of a polymerizable monomer and the scattering of chips of a fibrous reinforcing material during the operation.
Heretofore, on the rooftops and verandas of concrete structures such as condominiums and apartments, the verandas of wooden structures such as houses, and metallic structures such as bridges, waterproof construction has been carried out by the use of waterproof materials described in Japanese Architectural Standard Specification JASS8 Waterproofing and Sealing (published by Architectural Institute of Japan) of the same, for example, an bitumen waterproof material, a synthetic polymer sheet waterproof material and a liquid-applied compounds for waterproofing membrane coating typified by a polyurethane resin for the purpose of preventing the leaking of water.
In this connection, the above various waterproof materials have excellent waterproof performances, but the waterproof materials and waterproof layers are required to have various performances such as not only waterproof properties but also walking properties, anticorrosion, heat insulating properties, sound insulating properties, applicability, aesthetic properties and economy. Therefore, these waterproof materials have been selectively used in compliance with a purpose and a use.
The bitumen waterproof material has widely used because of reliability based on its thickness and a low cost. However, this material is not suitable for walking when it is used as the exposed waterproof material, and it is necessary to form a hard protective layer by a covering mortor or the like, which requires a prolonged application period and a much cost. Additionally, as a load of protection layer is about 120 kg/m.sup.2 the building structure has to posses high strength.
Furthermore, in the synthetic polymer sheet waterproof material, its application period is short, and the reliability of its thickness is high because of factory production. However, this kind of waterproof material inconveniently requires smooth substrate and in addition, a surface hardness is low and adhesive properties to the substrate are poor. Accordingly, in order to form a waterproof layer for walking, the formation of the protective layer is necessary, as in the above bitumen waterproof material.
On the other hand, the liquid-applied compounds for waterproofing membrane coating is excellent in aesthetic properties and compatibility with the substrate, and the walking resistance strength, the surface hardness and adhesive properties of the material can be ensured by selecting a suitable kind of material, even in the case that it is used for exposed waterproofing. As the liquid-applied compounds for waterproofing membrane coating, the polyurethane resin waterproof material has been most widely used, but in recent years, an FRP waterproof material having the higher walking properties has been spread which comprises an unsaturated polyester resin and a glass fiber reinforced material. This FRP waterproof material is excellent in water resistance and anticorrosion and has the high adhesive properties to the substrate and the high surface hardness, and for these reasons, the FRP waterproof material is suitable for the formation of the waterproof layer for walking (Japanese Patent Application Laid-open No. 142323/1992).
However, the liquid-applied compounds for waterproofing membrane coating is a field reaction type, and so the reaction is affected by a atomospheric temperature, which makes it difficult to control the curing reaction. Hence it is difficult to ensure the uniform thickness of the waterproof layer. In addition, in the waterproof application by the use of the FRP waterproof material, a step of laminating the resin and the fiber reinforced material on each other in the atmosphere is repeated plural times, and the resin is then cured to form the waterproof layer. At this time, there are some problems of environmental pollution, for example, the generation of an odor of a volatile solvent and a monomer contained in a primer or the like, and the scattering of chips of a fiber reinforced material. Moreover, follow-up properties to cracks of the substrate are poor, and breaks occur in the waterproof layer by zero span tension generated at the cracks, so that the trouble of the water leakage is liable to take place.
In contrast to the liquid-applied compounds for waterproofing membrane coating, Japanese Patent Application Laid-open No. 186744/1988 has disclosed a photo-setting resin reinforcing plastic prepreg sheet, and it has also described the application of the plastic prepreg sheet to a waterproof use. This prepreg sheet scarcely gives rise to environmental problems such as the scattering of chips of the fiber reinforced material and the generation of the monomer odor, and it has a prompt and simple applicability. However, the prepreg sheet has the drawback of the FRP waterproof material that the follow-up properties to cracks of the substrate are poor, so that the breaks occur in the waterproof layer.
On the contrary, Japanese Patent Application Laid-open No. 219242/1989 has disclosed a composite method of an FRP layer and a polyurethane resin layer. This is an excellent waterproofing method having the combined features of both the waterproof materials, but in the composite method, the problems of the difficulty of the curing reaction control and the thickness nonuniformity of the waterproof layer which the conventional liquid-applied compounds for waterproofing membrane coating have are not solved, and what is worse, the composite method has a drawback that an application period is long due to the double layers.
A theme of the present invention is to provide a waterproof material which sufficiently holds performances such as water resistance, weathering resistance, substrate adhesion, strength and follow-up properties to cracks of the substrate required for the waterproof material and which further possesses applicability, walking properties, improved operation environment and aesthetic properties, and another theme of the present invention is to provide a method for applying the waterproof material.